diff --git a/tests/utils/bazel/unit_test.bzl b/tests/utils/bazel/unit_test.bzl
index 41a18c8b3c..38ff4765e7 100644
--- a/tests/utils/bazel/unit_test.bzl
+++ b/tests/utils/bazel/unit_test.bzl
@@ -22,6 +22,11 @@ def lm_cc_test(name, deps = [], **kwargs):
     print a diagnostic message before aborting, without requiring any
     explicit setup call in test code.
 
+    SCORE_LANGUAGE_FUTURECPP_ASSERT_LEVEL_DEBUG is also defined so that
+    SCORE_LANGUAGE_FUTURECPP_ASSERT_DBG(_MESSAGE) checks actually compile in
+    (they're a no-op otherwise, see score/language/futurecpp's assert.hpp),
+    letting these invariants be exercised in unit tests.
+
     Args:
         name: Test target name.
         deps: Additional dependencies (assertion handler is appended automatically).
@@ -30,6 +35,7 @@ def lm_cc_test(name, deps = [], **kwargs):
     cc_test(
         name = name,
         deps = deps + ["//score/launch_manager/src/daemon/src/common:assertion_handler"],
+        defines = kwargs.pop("defines", []) + ["SCORE_LANGUAGE_FUTURECPP_ASSERT_LEVEL_DEBUG"],
         target_compatible_with = kwargs.pop("target_compatible_with", []) + select({
             "//config:unit_qemu": [],
             "//config:unit_host": [],